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12-02-2003, 12:47 PM
I built my own pair of speakers and I haven't gotten the chance yet to measure the impedance raiting on them yet. I figured my Sony STR-DE585 would be able to drive them. It handles 8-16 ohms. I figured these speakers would be 8 ohms, so I hooked them up as rears and after about and hour of listening to my music everything went silent. I went to the reciever to see "PROTECT" flashing in the display. My bad. I guess my speakers aren't 8 ohms. The unit was very hot. Whatever triggered it. Temperature protect or it realized the amps couldn't drive these...If that feature wasn't developed my reciever would probably be on fire right now. This is a very handy feature. Anyone ever had experiences like this? Any other cool features like this you know of? Please tell!

12-02-2003, 01:39 PM
The power supply components on a lot of Sony's receivers (especially the DE series models) have had problems in recent years, and some of them are known for running hot and being a bit touchy with low impedance speakers. I know that a lot of car speakers and subwoofer drivers are 4 ohms, but I don't know about DIY home speaker drivers. The protection mode does exactly what you say it does, protects the amp and prevents overloads. But, some of them aren't as well designed as others. With some receivers, the protection mode locks up the entire receiver and requires a service call to reset the unit. Others are very sensitive and go into protection mode very frequently.

Check the back of the unit and see if it has an impedance selector switch (I believe that UL now requires one for amplifiers to get their approval). In the 8 ohm position, the protection mode will engage a lot sooner than in the 4 ohm position. But, even in that more fault tolerant position, you still might run into problems if you're driving multiple speakers and some of them have highly variable impedances.

12-02-2003, 03:29 PM
I wasn't planning on using these speakers in my HT setup anyway. Just had them to try them out until I bought an amp for them. There's no selector switch. It only handles 8-16 ohm speakers. All I did was turn the unit off, unhook the speakers. After it cooled down, I turned it back on and it was fine. But what can you do. It did it's job. It protected itself because the speakers had too much resistance. That's what it's supposed to do and it did! So I can't complain!..My Sony DVD player also has a self diagnosis thing. Never had to use it before, but it says that if the player has a problem, it shows a code. You tell this code to an autorized Sony dealer, they know exactly what is wrong. Cool hey? If it works or not i'm not sure. But it sounds cool!